The present invention relates to an electrophotographic photoconductor comprising, on an electroconductive support material, a photoconductive layer containing a bisazo pigment having a certain novel structure of substituents, which electrophotographic photoconductor exhibits relatively high photosensitivity and usefulness for electrophotographic copying.
Certain bisazo compounds are known as being useful as photoconductive materials for use in electrophotographic processes. For instance, in U.S. Pat. No. 3,898,084 there are disclosed the bisazo compounds Diane Blue (C.I. 21,180), which is chemically 3,3'-dimethoxy-4,4' diphenyl bis-(1"-azo-2" hydroxy-3"-naphthanilide), Chlorodiane Blue, which is chemically 3,3'-dichloro-4,4' diphenyl bis-(1"-azo-2" hydroxy-3"-naphthanilide), and other bisazo compounds having similar structures as those of the afore-mentioned two, but with different substituents. In that U.S. Patent, those bisazo compounds are used as charge generators, in the form of small particles in a charge transport medium of the photoconductor.
Further, U.S. Pat. No. 4,052,210 discloses a reproduction element for use in electrophotographic copying processes, comprising, on an electroconductive support material, a photoconductive layer containing dispersed in a binder a bisazo naphthol compound having a certain structure of substituents.
Of the photoconductors produced from the above-mentioned photoconductive materials, some can be used in practice, but not all of them are satisfactory for practical use in terms of their photosensitivities.